Related stories::

Women who live beside busy roads are at a greater risk of breast cancer, a study claims.

It found those exposed to high levels of air pollution were more likely to have dense breast tissue — which raises the risk of developing the disease.

The research looked at nearly 280,000 women, ranking pollution in their area.

For every unit increase in smog, their chance of dense breasts increased four percent.

Team leader Dr. Lusine Yaghjyan, of the University of Florida, told the journal Breast Cancer Research:

“We found a positive association between fine particle concentration exposure and breast density, a well-established and strong breast cancer risk factor. Future studies are warranted to determine if the observed associations are causal.”

Some 55,000 women are diagnosed with the disease in the UK each year, with around 11,000 dying.

Last night Baroness Delyth Morgan, of Breast Cancer Now, said: “This is a thought-provoking finding. Further research is now needed.”

And Catherine Priestley, of Breast Cancer Care, said: “Having dense breasts is a known risk factor, so new insight is welcome.”

“However, we cannot see this in isolation. Breast cancer is complex and it is not possible to pinpoint any one cause.”

Fiona Osgun, of Cancer Research UK, was not convinced by the research. She said: “There is no evidence linking air pollution to breast cancer.”